Receiver and transmitter for telephone desk sets



P 17, 1940- G. CHEVASSU$ RECEIVER AND TRANSMITTER FOR TELEPHONE DESK SETS 5 Sheets-Sheet 1 Filed May 27, 1936 VOLUME CONTROL 5s/ IOOOn. 8 9

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INVENTOR. GZASTAVE G/El/A 5505 Se t. 17, 1940. G. CHEVASSUS 2,214,992

' RECEIVER AND TRANSMITTER FOR TELEPHONE DESK SETS Filed May 27, 1936 3 Sheets-Sheet 2 Sept. 17, 1940. e. cHEvAssUs RECEIVER AND TRANSMITTER FOR TELEPHONE DESK SETS Filed May 27, 1936 3 Sheets-Sheet 3 6' INVENTOR.

O6TAUE HEM ssus BY p o I! v 1 I RNEYS.

Patented Sept. 17,1940 2,214,992

UNITED STATES PATENT orrica RECEIVER AND TRANSMITTER. Font TELEPHONE nasx SETS Gustave Chevassus, San Francisco, Calif. Application May 27, 1936, Serial No. 81,9715

, 4 Claims. (01. 179-81) I This invention relates particularly to a sound Fig. 6 is an end view partly in section, taken on receiving and transmitting device to be used in the line 8-8 of Fig.4. conjunction with the mouth piece and ear re- Fig. 7 is a section taken through the switch for ceiver of a telephone, whereby amplification of making and breaking contact in thesound amplithe sound being received and sent is accomfying circuit when the telephone receiver-trans- 5 pllshed; mitter is placed thereon or removed therefrom.

An object of the invention is to provide a cab- Fig. 8 is a schematic diagram of the sound inet of small and compact size containing a pair amplifying circuits where direct current or batof tube circuits for sound amplification. one of tery current is used.

10 saidv circuits having a microphone adjacent the The invention to be hereinafter described con- 10 telephone receiver, and a loud speaker connected sists of a relatively small cabinet or box I, contherewith, while the other circuit is provided with taining a pair of like circuits for the amplificaa microphone and a loud speaker adjacent the tion of incoming and outgoing sounds, and havtelephone transmitter, said circuits being rening a bracket 2 onthe upper side thereof to supdered operative by placing a combined receiver port a combined telephone receiving and trans- 15 and transmitter thereon, and inoperative when mitting member generally designated by the nuthe-receiver-transmitter is removed therefrom. meral 3, which member includes the mouth piece A further object of the invention is to provide a or transmitter 4, and the receiver or ear piece 5. sound amplifying set to be placed on a desk, and In operation the member 3 is placed on the on whichatelephone transmitter-receiver may be bracket 2 so that the transmitter 4 registers 20 placed to enable the occupant of the desk to conwith a loud speaker Whieh Opens 011i; through verse over the telephone through the sound amthe up Side Of the box While t r eiver 5 plifying set without having to support the tele-, r i ters w t a m r p 1, l k wis p n phone receiver-transmitter in the hand. out through the pp e Of t e box Sound A still further object of the invention is to prowhich comes through e e e ver 5 actuates the 5 vide a sound amplifying apparatus to be used in mielephone which in turn, through an p conjunction with a telephone receiver-transmitfyihg circuit. amplifies e S u d broadcasts ter, that will be' superior in point of simplicity, it through the loud Speaker in e front of the inexpensiveness of construction, positiveness of box microphone 9 D de 0n t e r nt of operation, and facility and convenience in use the box 15 connected through a amplifying 30 and general efilciency. cult with the loud speaker 6, whereby the out- In this specification and the annexed drawings, 8 5 Sounds are amplified e e being breedthe invention is illustrated in the form considered cast Into telephone Pransmltter to be the best, but it is to be understood that the Th ampllfyine circults are operatedky alterinvention is not limited to such form, because it natmg current, a manually Operable Swltch m 36 may be embodied in other forms; audit is also to the from? of the box being provided to make be understood that in and by the claims following and break connection with e upp of ourthe description, it is desired to cover the invention e A Switch 15 9150 Provided in the Current in whatsoever form it may be embodied. circuit consisting of a stationary contact member 40 In the accompanying drawings: ii and a movable contact member l2, the mov- 40 Fig. 1 represents a perspective view of a teleable contact member having a plunger ii! therephone desk set and a sound amplifying set conon which is slidably confined in the bracket 2. structed in accordance with my invention, and A spring. i4 is provided around the plunger l3 showing the telephone receiver-transmitter supto maintain the plunger in an elevated position ported upon my sound amplifying apparatus. to cause the circuit through the switch members 45 Fig. 2 is a schematic diagram of the circuits ii and I2 to be broken. When the telephone used in my sound amplifying apparatus, where altransmitter-receiver element is placed on the ternating current is used. bracket 2, it causes the plunger i3 to be moved Fig. 3 is a plan view of my sound amplifying downwardly and to establish contact between the set showing the telephone transmitter-receiver switch members II and i2. Thus whenever the 50 thereon. v telephone receiver-transmitter is placed on the Fig. 4 is a front elevation of Fig. 3. supporting bracket 2, the sound amplifying cir- Fig. 5 is an end view partly in section taken on cults are immediately energized, and sound amthe line 55 of Fig. 4. plification will be accomplished through the set, 55

both to and from the telephonetransmitter-receiver.

The incoming alternating current is connected to one side of a transformer IS, the other side of said transformer l5 having conventional connections toa full wave rectifying tube l6. v The rectified current is connected through wires I I to each pair of amplifying circuits, between the tubes in said circuits which produce the various stage audio amplifications in said circuits.

In Fig. 2 the uppermost circuit consists of a microphone 'I connected to the speech input transformer l8. A volume control I 9 works 011 of the transformer l8 and connects to the grid of the detector tube 20. The output of the detector tube passes into two speech audio amplifiers consisting of the first stage tube 2| and the second stage tube 22, the second stage tube 22 being connected to the loud speaker 8. The other amplifying circuit consists of the microphone 9 connected to the speech input transformer 23. A volume or modulator control 24 works off of said transformer and is in turn connected to the amplyfying tubes 25 and 26, the last stated amplifying tube being connected to the loud speaker 6.

Inasmuch as the circuits and the necessary connections for the tubes, the various resistances, condensers, et'c., form no part of the present invention, and many forms of amplifying hook-ups might be provided, it is to be understood I do not limit myself specifically to the wiring diagrams shown, and for that reason the circuitdiagrams have not been specifically described.

In Fig. 8, a pair of circuits are shown for use in connection with battery current, there being one complete circuit for the amplification of the incoming sound, and another circuit for the amplification of the outgoing sound.

The incoming sound amplifying circuit includes the microphone 1', speech input transmitter l8, volume control I 9', detector tube 20, the first stage audio frequency coupling transformer 21, the first stage amplifying tube 2|, the second stage audio frequency coupling transformer 28, the second stage amplifying tube 22', and the loud speaker 8'.

In the companion circuit, I have provided the microphone 9, the speech input transformer 23', the volume control 24, detector tube 25', the first stage audio frequency tube 26', the second stage audio frequency coupling transformer 30, the second stage amplifying tube 3| and the loud speaker 6 Where either alternating or battery current is used for energizing the circuits, the signal or sound is successively increased in volume after passing through the audio frequency circuits.

An annular resilient collar 35 is provided around the loud speaker 6 and the microphone 1 where the same project through the upper face of the cabinet, to establish a temporary soundproof connection with respectively the receiver and the transmitter of the telephone, thus preventing extraneous sounds from interfering with the sounds being transmitted from the telephone apparatus to the sound amplifying apparatus.

Having thus described this invention, what I claim and desire to secure by Letters Patent is:

1. -An auxiliary pick up and amplifying means for use with a telephone transmitter and receiver, comprising a portable containe a depressible bracket on said container to support a unitary receiving and transmitting instrument of a telephone hand set, a switch associated with said bracket and closed by the depression thereof upon the placing of said instrument thereon, means automatically opening said switch upon the removal of said instrument from said bracket, a microphone in said container adjacent the receiver of said instrument when the same is placed on said bracket, an amplifier and loud speaker in said container operatively connected to said microphone for amplifying incoming sounds picked up thereby, a second amplifier and loud speaker in said container adjacent to the transmitter of said instrument when the same is placed on said bracket, a second microphone in said container operatively connected to said second amplifier and loud speaker for transmitting outgoing sounds thereto, separate electric circuits for each microphone-amplifier and loud speaker, each of said circuits being energized by the closing of said switch.

2. The structure of claim 1, and means for modulating the volume of sound passing through each of said circuits.

3. An auxiliary pick up and amplifying means for use with a telephone transmitter and receiver, comprising a portable cabinet, means on said cabinet for supporting the receiver and transmitter of a telephone instrument thereon, a normally open switch in said cabinet, said means on said cabinet being operatively connected to said switch for closing the same when said instrument is placed thereon, a microphone in said cabinet adjacent the receiver of said instrument when the same is placed on said means, an amplifier and loud speaker in said cabinet operatively connected to said microphone for amplifying incoming sounds picked up thereby, a second amplifier and loud speaker in saidcabinet adjacent to the transmitter of said instrument when the same is placed on said means, a second microphone in said cabinet operatively connected to said second amplifier and loud speaker for transmitting outgoing sounds thereto, separate electric circuits for each microphone-amplifier and loud speaker, each of said circuits being energized by the closing of said switch. v

4. The structure of claim 3, and means for modulating the volume of sound passing through each of said circuits.

GUSTAVE CHEVASSUS. 

